More recently I have begun using Linux at home as opposed to windows. I made the switch because in all my life I have never once purchased windows, and its a real pain in the ass to find a copy that will work. I'm tired of feeling like some sort of criminal by using company license keys or by asking a friend for a copy. To skip the story, we now have three linux based devices - two android phones and a desktop, and have made quite a few discoveries about how they line up.
In terms of what an operating system can do, Windows is not any better out-of-the-box than linux, and in fact lacks the inclusion of an office suite, powerful photo editor and/or graphics, and no instant messaging. Anyone that has installed a fresh version of Windows knows that once you've installed the OS, you must continue to install everything you want to use.
The most popular versions of linux run surprisingly well straight from a CD and come with the software you want and need. Spend an hour downloading images of ubuntu, fedora, linova, mint, or slackware and boot the computer from the cd. You will be surprised to find that in 60 seconds you're able to surf the web, open office documents, edit photos, and more, and without having to install anything. Boot up a Windows CD and see what you get.
Probably the nicest thing linux has to offer is its speed and reliability (assuming you don't break it by doing something stupid). Gone are the mysterious freezes and delays of Vista and Win7. Linux still runs well on Pentium 1 and 2 processors with 64MB of RAM. That means your computer does not get old and slow, it just remains your computer.
But there is a price to be paid in frustration with linux. For the typical windows power user, linux strips away all your microsoft super powers and replaces them with confusion and anger. DOS is gone, so are many are of the commands, and it is sensitive to capitalization. Linux cannot find "documents" only "Documents."
Googling questions on how to do stuff becomes second nature. It takes some real patience and a real desire to become a linux "power user," something I have yet to accomplish.
At the end of the day, it becomes an issue of "how do I want to spend the end of my day?" You can spend money for slower, familiar software, or you can test your patience with fast, reliable, frustrating software. In the end Windows leaves me feeling poor, slow, but smart. Linux makes me feel fast and stupid.